-Aa8  «a-ia^  Co/w/ 

s — } 


C*P«^ 


CONNECTICUT 

AGRICULTURAL  EXPERIMENT  STATION 

NEW     HAVEN,    CONN. 


BULLETIN    129,    MAY,    1899. 


Inspection  and  Care  of  Nursery  Stock. 


CONTEXTS. 

Page. 

Notice  as  to  Bulletins  and  Reports 2 

Inspection  and  Care  of  Nursery  Stock 3 

Legislation . 3 

Scale  in  Connecticut 3 

Nursery  Inspection  in  Connecticut 3 

Notice  to  Connecticut  Nurserymen 4 

Nursery  Practices 5 

Suggestions  to  Orchardists 6 

Value  of  Certificates 6 

Treatment - 7 

Fumigation 7 

Kerosene  and  Water 8 

"Whale-oil  Soap 8 

Summary 8 

Appendix.     General  account  of  the  San  Jose  Scale .-  9 


ho  4  I  A( 


2         CONNECTICUT   EXPERIMENT   STATION,    BULLETIN    128. 


Notice  as  to  Bulletins. 

The  Bulletins  of  this  Station  are  mailed  free  to  citizens  of 
Connecticut  who  apply  for  them,  and  to  others  as  far  as  the 
limited  editions  permit. 

Applications  should  be  renewed  annually  before  January  1st. 

The  matter  of  all  the  Bulletins  of  this  Station,  in  so  far  as  it  is 
new  or  of  permanent  value,  will  be  made  part  of  the  Annual 
Report  of  the  Station  Staff. 

All  Bulletins  earlier  than  No.  71  and  Nos.  72,  83,  86,  93,  10Q, 
101,  102,  111  and  118  are  exhausted  and  cannot  be  supplied. 


Notice  as  to  Supply  oe  Station  Reports. 

The  Station  has  no  supply  of  its  Annual  Reports  for  the  years 
1877,  1878,  1879,  1880,  1881,  1882,   1883,  1887  and  1891. 

The  Annual  Report  of  this  Station,  printed  at  State  expense, 
is  by  law  limited  to  an  edition  of  7,000  copies. 

After  exchanging  with  other  Experiment  Stations  and  Agricul- 
tural Journals,  the  Reports  remaining  at  the  disposal  of  the 
Station  will  be  sent  to  citizens  of  Connecticut  who  shall  season- 
ably apply  for  them,  and  to  others  as  long  as  the  supply  lasts. 


Former  Reports  Wanted. 

There  is  frequent  call  for  our  earlier  Annual  Reports  on  the 
part  of  public  libraries,  students,  chemists,  naturalists,  and 
station  workers. 

Persons  who  can  supply  copies  of  Reports  for  any  of  the  years 
above  named,  will  be  likely  to  find  purchasers  by  communicating 
with  the  Director. 


INSPECTION    AND    CARE    OF   NURSERY   STOCK.  3 

INSPECTION   AND   CARE   OF   NURSERY   STOCK. 
By  W.  E.  BEiTTOisr. 

Legislation. — In  fifteen  States,  laws  have  been  enacted  provid- 
ing for  the  inspection  of  nursery  stock  and  in  some  cases  of 
orchard  trees  as  well.  The  object  of  this  inspection  is  to  find 
out  whether  or  not  certain  noxious  insects  and  fungi  are  present 
which  threaten  the  fruit-growing  interests  of  the  whole  State  and 
to  prevent  their  spread  by  the  sale  of  infected  nursery  stock.  At 
this  writing  similar  measures  are  awaiting  legislative  action  in 
five  other  States.  Connecticut,  as  yet,  has  no  such  inspection 
laws. 

This  legislation  has  been  mostly  occasioned  by  the  San  Jose 
scale,  a  pest  which  can  be  extirpated  by  prompt  treatment  and 
which  if  permitted  to  live  will  surely  destroy  not  only  our  fruit 
orchards  but  also  many  ornamental  trees  and  shrubs. 

The  San  Jose  scale  has  been  distributed  chiefly  by  means  of 
nursery  stock.  The  inspection  laws  of  different  States  vary  con- 
siderably in  their  requirements,  causing  much  annoyance  to 
nurserymen  desiring  to  ship  stock  into  these  States. 

The  Scale  in  Connecticut. — The  San  Jose  scale  has  been  found 
in  over  twenty  towns  of  this  State,  some  of  them  containing 
several  distinct  infested  localities  and  mostly  situated  along  the 
coast.  The  central  portion  of  the  State  as  far  north  as  Hartford 
has  also  been  invaded,  and  probably  there  are  other  infested 
areas  not  yet  brought  to  our  knowledge. 

Niirsery  Inspection  in  Connecticut. — Since  the  laws  of  neigh- 
boring States  debar  Connecticut  nurserymen  from  shipping 
nursery  stock  into  such  States  unless  accompanied  by  a  certificate 
of  inspection,  this  Station  has  deputed  a  member  of  its  staff  to 
inspect  nurseries  upon  application  of  the  owners  and  to  give  cer- 
tificates, in  case  no  scale  or  other  pests  of  a  serious  nature  are 
found.  Early  in  1899  regulations  were  formally  adopted  by  the 
Station  Board  of  Control  regarding  such  inspection  and  the 
granting  of  certificates.  The  following  circular  embodies  these 
rules  and  has  been  already  mailed  to  about  seventy  nurserymen, 
seedsmen,  and  plant  dealers. 


4  CONNECTICUT   EXPERIMENT    STATION,    BULLETIN    129. 

The  Connecticut  Agricultural  Experiment  Station. 
new  haven,   conn. 


Notice  to  Connecticut  Nurserymen. 

Some  States,  to  which  Connecticut  nurserymen  frequently  ship 
nursery  stock,  have  laws  designed  to  prevent  the  further  dissem- 
ination of  certain  insect  and  fungous  pests,  by  requiring  that  all 
stock  brought  into  these  States,  shall  come  from  inspected  nur- 
series in  which  none  of  these  diseases  have  been  found,  and  that 
a  copy  of  the  inspection  certificate  shall  accompany  each  shipment. 

In  answer  to  requests  from  nurserymen,  this  Station  has  made 
inspections,  and  has  given  certificates  when  the  stock  was  not 
found  infested  or  diseased. 

The  following  information  is  given  for  the  benefit  of  those  who 
may  hereafter  apply : 

1.  One  of  the  Station  staff,  competent  to  do  the  work,  will 
inspect  any  nursery  in  the  State  upon  the  written  application 
of  the  owner  ;  there  will  be  no  charge  for  the  services  of  the 
inspector,  but  his  traveling  and  incidental  expenses  are  to  be 
paid  by  the  nurseryman. 

2.  If  no  indications  of  San  Jose  Scale  or  other  serious  insect 
pest,  or  of  dangerous  infectious  diseases  are  found,  a  certificate 
to  that  effect  will  be  given. 

If  any  one  of  these  dangerous  insect  pests  or  diseases  is  found, 
no  certificate  will  be  given. 

3.  The  certificate  will  be  in  the  following  form  : 

"  This  is  to  Certify,  That  on — 

189 the  %inder signed  inspected  the  stock  in  the  nursery  of 

of  -  -- ----, 

Conn.,  and  found  no  evidence  of  the  presence  of  San  Jose  Sccde, 
or  other  dangerously  injurious  insect  or  fungous  pests,  liable  to  be 
introduced  into  orchards,  upon  nursery  stock.'''' 

This  form  of  certificate  may  be  modified  by  the  Station  if  con- 
sidered desirable. 

4.  Whether  scale  or  dangerous  diseases  are  found  or  not,  the 
nursery  will  not  be  again  inspected  until  after  one  growing  season 
has  passed. 


INSPECTION   AND   CARE   OF  NURSERY   STOCK.  5 

5.  Upon  evidence  of  the  fraudulent  use  or  abuse  of  certificates 
by  any  nurseryman,  the  Station  may  refuse  to  make  inspections 
for  him  in  the  future. 

6.  When  stock  is  known  to  be  infested,  nurserymen  must  take 
vigorous  measures  to  eradicate  the  trouble  from  it.  The  Station 
will  give  advice  as  to  the  best  methods  of  procedure.  Where 
such  measures  are  promptly  taken  by  the  owner  of  the  nursery, 
the  Station  will  not  ordinarily  make  known  the  names  of  nursery 
firms  having  infested  stock.  The  Station,  however,  reserves  the 
right  to  publish  this  information,  and  will  do  so  when  the  safety 
and  welfare  of  the  public  seem  to  demand  it. 

Nursery  Practices. — As  nurserymen  and  tree  dealers  generally 
buy  more  or  less  of  their  stock  from  various  localities,  it  is  not 
improbable  that  most  of  them  at  some  time  have  thus  brought 
the  scale  into  their  nurseries.  Whether  the  insect  has  remained 
there  and  developed  or  not  has  depended  largely  upon  their  busi- 
ness methods.  One  object  of  this  bulletin  is  to  call  attention  to 
the  fact  that  certain  practices  are  favorable  to  the  development 
and  increase  of  the  scale  ;  and  that  if  such  practices  are  abandoned 
an  infested  nursery  may  more  readily  become  clear  of  this  pest. 
First  of  all  the  nurseryman  should  make  himself  familiar  with  the 
appearance  and  habits  of  the  scale  insect  and  should  carefully 
watch  his  stock.  Although  much  has  been  published  about  the 
insect,  there  are  yet  nurserymen  who  have  never  seen  it  and 
apparently  have  taken  no  trouble  to  inform  themselves  regard- 
ing it. 

Experience  shows  that  in  a  scale-infested  nursery  the  insects 
are  found  most  commonly  and  abundantly  upon  left-over  stock 
which  has  been  planted  out  and  allowed  to  remain  in  nursery 
rows  sometimes  for  three  or  four  years.  If  any  of  this  stock  was 
even  slightly  infested  when  it  was  first  received  into  the  nursery, 
the  insects  have  had  time  to  multiply  and  become  so  numerous 
that  they  are  easily  detected  by  the  inspector.  Such  stock  is 
rarely  of  much  value,  and  the  nurseryman  would  do  better  to 
destroy  it  rather  than  let  it  remain  as  a  breeding  place  for  pests 
of  all  kinds.  All  unsaleable  stock  should  be  promptly  destroyed 
by  fire  and  the  remainder  fumigated  or  otherwise  treated  before 
planting  out. 

The  official  inspector,  in  examining  nursery  stock,  will  properly 
look  over  with  the  greatest  care  those  trees  which  most  commonly 


6         CONNECTICUT   EXPERIMENT   STATION,   BULLETIN    J  29. 

are  found  infested,  viz  :  apple,  pear,  plum  and  quince.  The  San 
Jose  Scale  will  attack  many  other  kinds  of  trees  and  shrubs. 

Scales  are  not  as  likely  to  be  disseminated  on  blackberry  and 
raspberry  stock  as  upon  fruit  trees  because  their  tops  are  cut  off 
and  burned  previous  to  shipping  the  plants.  Peach  stock  is  also 
less  liable  to  become  badly  infested  in  the  nursery  on  account  of 
its  rapid  growth. 

The  proprietor  or  foreman  who  works  continually  amongst  the 
trees,  if  he  will  take  the  trouble  to  acquaint  himself  with  the 
scale,  should  be  the  best  inspector.  He  has  opportunity  to  exam- 
ine the  stock  when  it  is  received,  when  it  is  planted  out,  during 
all  its  growth,  and  finally  when  it  is  dug  and  prepared  for  ship- 
ment. The  official  inspector,  in  making  his  tour  of  the  nursery, 
may  overlook  insects  or  fungi  that  would  not  fail  to  be  detected 
if  he  had  frequent  occasion  to  traverse  the  ground. 

Suggestions  to  Orchardists. — It  is  quite  as  important  for  the 
orchardist  as  for  the  nurseryman  to  treat  his  trees  before  plant- 
ing out.  The  nurseryman  should  not  be  wholly  blamed  for  the 
increase  and  spread  of  the  scale.  Many  trees  are  planted  each 
year  only  to  be  neglected,  and  if  such  trees  are  infested,  all  trees 
in  the  immediate  vicinity  soon  become  so.  Trees  can  be  treated 
much  more  effectively  and  economically  before  they  are  planted 
than  afterwards.  If  it  is  not  feasible  for  the  fruit  grower  to 
fumigate  them,  they  can  easily  be  dipped,  while  bunched,  into  a 
solution  of  whale-oil  soap.  The  tops  should  first  be  well  pruned 
and  if  the  soap  solution  is  in  a  barrel  or  deep  tank,  a  bunch  of 
trees  can  be  plunged  into  it,  top  first,  as  far  as  the  roots.  It  is 
perhaps  best  not  to  dip  the  roots.  This  method  has  been  prac- 
ticed by  at  least  one  Connecticut  fruit-grower.  The  expense  of 
such  treatment  is  very  slight. 

Value  of  Certificates. — The  certificate  states  that  an  examina- 
tion has  been  made  and  that  certain  insects  and  diseases  have  not 
been  found.  It  does  not,  however,  guarantee  or  imply  that  they 
are  altogether  absent.  These  pests  are  so  difficult  to  detect, 
when  present  in  small  numbers  on  a  few  trees,  that  no  person 
can  so  thoroughly  examine  a  nursery  of  ordinary  size  as  to  be 
warranted  in  stating  that  it  is  absolutely  free  from  them.  If 
they  are  but  moderately  abundant  in  any  portion  of  the  nursery 
the  inspector  will  readily  find  them.  The  value  of  a  certificate, 
then,  is  to  show  that  a  careful  inspection  has  been  made  by  a 
competent  person,  and  that  the  inspected  nursery  is  reasonably 
free  from  dangerous  diseases  and  pests. 


INSPECTION   AND   CAEE   OF   NURSERF   STOCK.  7 

Treatment. 

There  are  three  methods  by  which  the  San  Jose  scale  may  be 
destroyed  with  little  trouble  or  expense,  viz.:  (1)  Fumigating 
with  hydrocyanic  acid  gas.  (2)  Spraying  with  kerosene  and 
water.  (3)  Spraying  with  or  dipping  the  trees  in  a  solution  of 
whale-oil  soap. 

For  nursery  stock,  fumigation  is  probably  the  most  efficient 
and  cheapest  treatment.  It  is  attended,  however,  by  more  or  less 
danger  to  the  operator  and  should  never  be  entrusted  to  careless 
employes. 

Fumigation. — A  tight  box  or  house  is  necessary  in  which  to 
enclose  the  stock.  If  the  nursery  is  an  extensive  one  it  would 
probably  pay  to  erect  a  house  of  two  rooms  for  the  purpose.  The 
walls,  roof  and  floor  of  such  a  house  should  be  double  boarded 
with  heavy  building  paper  between  to  make  it  gas-tight.  A  suit- 
able number  of  doors  should  be  arranged  for  convenience  in  fill- 
ing and  taking  the  trees  from  the  house.  Roof  ventilators  which 
can  be  opened  and  shut  from  the  outside  are  a  convenience.  A 
house  of  this  kind  is  inexpensive,  and  may  be  used  as  a  storehouse 
when  not  needed  for  fumigating  purposes.  For  a  small  nursery, 
however,  a  tight  box  large  enough  to  take  in  fruit  trees  may  be 
used  to  good  advantage. 

Prof.  W.  G.  Johnson,  of  Maryland,  who  has  had  much  expe- 
rience in  fumigating  nursery  and  orchard  trees,  recommends* 
quantities  of  chemicals  as  follows  for  each  100  cubic  feet  of  en- 
closed space  : 

25  grams  (a  little  less  than  1  oz.)  (by  weight)  Potassium  Cyanide  98-99  per 
cent.  pure. 

\\  ozs.  (liquid  measure)  Sulphuric  Acid  best  grade  commercial  (sp.  gr.  1.83). 
\\  ozs.  (liquid  measure)  water. 

The  enclosed  space  should  be  computed,  and  the  chemicals 
meted  out  accordingly.  A  stoneware  jar  of  suitable  size  may  be 
used  as  a  generator.  The  water  should  always  first  be  put  in  this 
and  the  acid  poured  in  slowly  in  a  thin  stream  with  constant  stir- 
ring. After  filling  the  house  or  box  with  trees,  place  the  jar 
inside  and  within  easy  reach  of  the  door  or  lid.  The  cyanide  is 
dropped  into  the  jar  and  the  operator  should  leave  at  once,  and 
close  the  house  immediately  from  the  outside.  To  breathe  the 
fumes  may  be  immediately  fatal.  After  the  trees  have  been 
fumigated  for  half  an  hour  the  box  or  house  may  be  opened  from 

*  Maryland  Agr.  Exp.  Station  Bulletin,  57,  p.  93,  1898. 


8        CONNECTICUT   EXPEEIMENT   STATION,   BULLETIN   129. 

the  outside,  using  the  greatest  care  to  withdraw  at  once  to  a  safe 
distance.  Ten  minutes  should  elapse  before  anyone  attempts  to 
remove  the  trees.  The  trees,  if  dormant,  will  not  he  injured  if 
left  in  the  gas  a  much  longer  time  or  over  night.  This  treatment 
is  said  to  kill  every  form  of  animal  life,  and  the  operators  should 
use  every  precaution  in  handling  the  chemicals  and  generating 
the  gas  in  order  to  prevent  accidents. 

Cyanide  of  potassium  is  a  most  deadly  poison. 

Kerosene  and  water. — Kerosene  alone  has  been  used  as  a  spray 
on  plants  with  varying  results.  It  is  liable  to  injure  the  plants  and 
is  not  to  be  advised  for  that  reason.  But  kerosene  can  be  mixed 
with  water  under  pressure,  a  special  pump  being  required  for  the 
purpose.  Such  a  pump  made  by  the  Deming  Co.,  Salem,  Ohio, 
was  figured  in  Bulletin  126  of  this  Station,  p.  7.  A  similar  pump 
is  also  manufactured  by  the  Goulds  Mfg.  Co.  of  Seneca  Falls, 
N.  Y.  Two  seasons'  experience  in  fighting  San  Jose  scale  in 
New  York,*  shows  that  1  part  of  kerosene  to  4  parts  water  (a  20 
per  cent,  mixture)  will  kill  the  scale  and  not  injure  the  plants. 

Whale-oil  Soap. — If  one  does  not  care  to  fumigate  or  go  to  the 
expense  of  buying  a  special  pump  for  kerosene  and  water,  he  can 
destroy  nearly  all  the  scales  by  dipping  or  spraying  the  dormant 
trees  with  the  following  solution  : 

Whale-oil  soap 2  lbs. 

"Water 1  gallon. 

If  the  trees  are  in  foliage,  one  pound  of  soap  in  five  gallons  of 
water  may  be  used,  but  this  will  probably  kill  only  the  very 
young  scales. 

Summary. 

1.  Most  of  the  inspection  laws  are  specially  aimed  at  the  detec- 
tion and  destruction  of  the  San  Jose  Scale. 

2.  Inspections  are  of  great  value,  but  certificates  are  not  proof 
that  no  scale  exists  in  the  nursery. 

3.  Nurserymen  should  either  destroy  all  left-over  stock  or  treat 
it  before  setting  out  in  nursery  rows. 

4.  The  orchardist  should  also  apply  some  treatment  to  the  trees 
before  planting  permanently  in  the  orchard. 

5.  Fumigating  with  hydrocyanic  acid  gas  is  the  surest  and 
cheapest  method  of  destroying  the  scale  upon  nursery  stock,  but 
great  care  must  be  taken  in  using  the  gas,  as  it  is  very  poisonous. 

6.  Spraying  with  kerosene  and  water  or  with  a  solution  of 
whale-oil  soap,  as  described  above,  is  also  effectual. 

*  Cornell  Univ.  Agr.  Exp.  Station  Bulletin,  155,  1898. 


INSPECTION   AND   CARE    OF    NURSERY    STOCK.  9 

APPENDIX. 

General  Account  of  the  San  Jose  Scale. 

Note. — The  following,  from  Bulletin  121,  published  in  1895,  is  here  reproduced 
for  the  benefit  of  those  who  are  unfamiliar  with  the  habits  and  appearance  of  the 
insect. 

Appearance  of  the  Scale. — When  the  scales  occur  singly 
they  are  not  easy  to  detect  with  the  naked  eye  ;  but  when,  as 
is  usually  the  case,  they  occur  in  groups,  they  are  easily  seen 
as  a  grayish  and  roughened  or  pimply  coating  upon  the  bark. 
This  coating,  when  scraped  off  with  the  thumb-nail  or  with 
the  blade  of  a  knife,  appears  mingled  with  a  yellowish  liquid  if 
the  insects  composing  it  are  alive.  In  severe  cases  the  bark  is 
completely  covered  with  this  scaly  coating,  and  upon  removing 
the  bark  the  delicate  tissues  beneath  are  seen  to  present  a  pinkish 
or  purplish  color.  When  a  tree  is  but  slightly  affected,  the  scales 
are  usually  found  singly  or  in  small  groups  upon  the  twigs,  often 
at  the  base  of  the  leaves.  The  separate  scales  measure,  when 
fully  grown,  about  one-eighth  of  an  inch  in  diameter,  are  almost 
circular,  slightly  convex  with  a  minute  blackish  projection  in  the 
center,  and  are  of  a  dirty  brown  or  gray  color.  The  scale  may 
be  easily  lifted  upon  the  point  of  a  pen-knife,  and  the  insect 
beneath  it,  if  alive,  is  seen  as  a  small  bit  of  yellowish  jelly.  This 
scale  differs  in  appearance  from  other  scales  commonly  found 
upon  fruit  trees  ;  it  is  rounder  than  the  "oyster-shell  bark  louse," 
and  is  smaller  and  darker  in  color  than  the  "  scurfy  bark  louse." 
In  fact  it  is  the  only  scale  among  those  commonly  found  on  fruit 
trees  in  Connecticut,  which  is  distinctly  circular  in  outline. 

Effect  of  the  scale  on  the  trees. — The  pernicious  effects  of  the  San 
Jose  scale  are  in  a  great  measure  due  to  its  inconspicuous  char- 
acter, and  to  the  fact  that  its  effect  upon  the  vitality  of  the  tree 
is  not  at  once  apparent.  During  the  first  season  of  its  attack,  the 
tree  may  be  apparently  health}'-,  with  full  leafage  and  abundant 
fruit.  As  the  scale  spreads,  however,  the  effect  becomes  more 
plainly  visible,  though  it  is  such  as  might  readily  be  attributed  to 
the  attacks  of  borers  or  to  drought.  Only  the  most  careful 
observation  will  discover  the  true  cause  of  disturbance.  Gener- 
ally by  the  second  or  third  season  only  does  the  scale  become  so 
abundant  as  to  be  conspicuous,  and  by  that  time  the  whole  tree 
is  infested  with  the  grayish  coating  of  scales ;  in  its  weakened 


10      CONNECTICUT   EXPERIMENT   STATION,    BULLETIN    129. 

condition  it  succumbs  easily  to  an  exceptionally  severe  winter, 
and  though  it  may  put  forth  leaves,  they  shortly  wither,  and 
before  the  cause  of  the  trouble  is  actually  known,  the  tree  is  prac- 
tically dead.  If  taken  in  time,  however,  it  is  not  difficult  to 
check  its  ravages,  and  we  would  therefore  urge  all  fruit-growers 
to  inspect  their  trees  with  care,  and  to  send  us  specimens  of  any 
insect  found  bearing  resemblance  to  this  scale. 

The  introduction  of  the  San  Jos6  scale  into  the  Eastern  States 
has  been  traced  to  the  importation  of  Japanese  plum  trees  into 
New  Jersey  from  California. 

Like  other  scale  insects,  the  San  Jose  scale  can  spread  only  a 
short  distance  each  year,  unless  its  distribution  is  aided  by  the 
agency  of  wind,  water,  or  animals. 

The  San  Jose  scale  survives  the  winter  in  a  half-grown  state. 
It  becomes  fully  developed  and  reproduces  about  the  last  of  May 
or  first  of  June.  The  newly-born  or  hatched  individuals,  unlike 
their  female  parent,  have  no  scaly  covering  but  crawl  about  like 
ordinary  plant  lice.  They  are  very  small  at  first.  The  period  of 
activity  lasts  but  a  day  or  two,  sometimes  only  a  few  hours,  when 
the  young  insects  settle  upon  the  bark  and  become  fixed. 

The  scaly  covering  then  begins  to  form.  The  insect  soon  molts 
and  the  cast-off  skin  uniting  with  a  waxy  secretion  forms  the  visi- 
ble external  scale. 

The  female  insect  cannot  change  her  place  after  the  scaly  cov- 
ering begins  to  form,  but  the  male  is  able  to  emerge  from  his 
cover,  and  being  winged  can  travel  short  distances. 


- 


University  of 
Connecticut 

Libraries 


